Brain Star Award Feature: Kassem Jaber, Montreal Neurological Institute

Kassem Jaber

A new framework to assess placement of electrodes in the brain for epilepsy surgery

Epilepsy is a chronic condition that is characterized by spontaneous recurring seizures. In clinical practice, the region which generates seizures is called the epileptic focus. The location of the focus can be localized by electrical measurement of brain activity, known as electroencephalography (EEG). This can be noninvasively placed on the scalp or invasively inserted into the brain for improved spatial accuracy. 30-40% of patients with epilepsy do not respond to antiseizure medication. For these patients a surgical intervention to remove the focus might be the only way to prevent seizures from occurring. However, currently only half of patients selected for surgery achieve post-operative seizure freedom. One reason may be due to the poor coverage of invasive electrodes in the brain tissue responsible for generating seizures. Research led by Kassem Jaber, working under the supervision of Dr. Birgit Frauscher at the Montreal Neurological Institute, resulted in the development of a spatial perturbation framework that evaluates whether invasive electrodes placed during pre-surgical evaluation adequately cover the epileptic focus.

Read the full story: https://can-acn.org/brain-star-award-winner-kassem-jaber/

Read the original scientific publication: Jaber, K., Avigdor, T., Mansilla, D., Ho, A., Thomas, J., Abdallah, C., Chabardes, S., Hall, J., Minotti, L., Kahane, P., Grova, C., Gotman, J. and Frauscher, B., 2024. A spatial perturbation framework to validate implantation of the epileptogenic zone. Nature Communications, 15(1), p.5253. https://rdcu.be/d6hnY

Brain Star Award Feature: Ghazaleh Eskandari-Sedighi, University of Alberta

Ghazaleh Eskandari-Sedighi Ghazaleh Eskandari-Sedighi

Identification of CD33m as a new protective factor in Alzheimer’s Disease development.

Immune cells in the brain, called microglia, are thought to be critical in Alzheimer’s disease (AD) development through numerous functions, including their ability to remove amyloid beta (Aβ), which is protein that accumulates in the brains of AD patients. In this study, Ghazaleh Eskandari-Sedighi, working in Matthew Macauley’s laboratory at the University of Alberta, focused on understanding the mechanism of action of a protein called CD33, which has been identified as one of the top-ranked drivers in the development of AD and that is predominantly found in microglia in the brain. By transferring different versions (called isoforms) of this protein in a mouse model of AD, they were able to show that these different isoforms have opposite effects on microglial cells and AD progression.

CD33 is a receptor that modulates immune response that exists in two forms:  a long isoform CD33M (Major) and a short isoform: CD33m (minor). Understanding how CD33 isoforms differentially impact microglial cell function has been challenging due to functional divergence between CD33 from mouse and humans. In this study, the researchers introduced the human CD33 gene in a mouse model of AD, which accumulates Aβ protein. In these mice, they found that CD33 isoforms have opposing effects on the response of microglia to Aβ accumulation. The larger CD33M increases the total level of Aβ and formation of plaques with a diffuse nature, which correlates with fewer number of microglia as well as higher number of dysfunctional neurons. In contrast, CD33m gives rise to opposite outcomes; beyond decreasing total Aβ levels, CD33m skews formation of compact Aβ deposits, correlating with increased microglia and fewer dysfunctional neurons. Overall, this work reveals how CD33, as a top genetic susceptibility factor for AD, is connected to microglial cell function.

Read the full story here: https://can-acn.org/brain-star-award-winnerghazaleh-eskandari-sedighi/

Scientific publication: Eskandari-Sedighi, G., Crichton, M., Zia, S. et al. Alzheimer’s disease associated isoforms of human CD33 distinctively modulate microglial cell responses in 5XFAD mice. Mol Neurodegeneration 19, 42 (2024).

https://doi.org/10.1186/s13024-024-00734-8

Read CAN’s brief submitted to the 2025 FINA Pre-budget consultations

We are happy to share with you CAN’s pre-budget brief submission for the Consultations launched by the Finance committee of the House of Commons.

https://can-acn.org/wp-content/uploads/2025/07/CAN-FINA-Submission-July-2025_final-1.pdf

Our two main recommendations are an effective doubling of tri-agency budget over the coming years, and increased investment in brain-related programs. 

We believe if multiple organizations submit similar recommendations, including the proposal to double tri-agency funds as a nation-building project, this could have some impact, and therefore wanted to share this with you in advance of the submission deadline, which is August 1st.

In case you missed it, here is the call for briefs:

https://www.ourcommons.ca/DocumentViewer/en/45-1/FINA/news-release/13575827

and here is a link to submit, should your organisation also want to weigh in:

https://www.ourcommons.ca/committees/en/FINA/StudyActivity?studyActivityId=13109197

Also note that individuals can also send in briefs, and that we will be encouraging CAN members to do so. 

It is also possible to send formal submission directly to the Department of Finances here:

https://www.canada.ca/en/department-finance/programs/consultations/2025/pre-budget-consultations-2025.html

The deadline for this second consultation  is Aug 28, and CAN will be sending a similar brief to this consultation also.

Brain Star Award Feature: Jessie Muir and Eshaan Sriram Iyer, McGill University

Jessie Muir & Eshaan Sriram Iyer

Discovery of differences in encoding threat discrimination in the brain of males and females

Learning to predict threat is essential, but equally important—yet often overlooked—is learning about the absence of threat. This study by Drs. Jessie Muir and Eshaan Sriram Iyer, working in the laboratory of Dr. Rosemary Bagot at McGill University, looks at mechanisms of threat encoding and discrimination in pathways relevant to depressive-like symptoms in mice. They identified sex differences in the circuits and mechanisms responsible for recognizing threats and suggest they may reflect differences in behavioral strategies that can be relevant for understanding sex differences in risk of psychiatric disorders.

Depression is currently the leading cause of disability worldwide yet current antidepressant treatments remain ineffective in around 50% of the population. Women are twice as likely to develop depression compared to men. Given most pre-clinical studies have looked exclusively at males, there is a large gap in knowledge in the mechanisms underlying the disorder in females. Depression involves a disruption in many adaptive behavioral processes including discriminating aversive from neutral events.

Read the full story here: https://can-acn.org/brain-star-award-winners-jessie-muir-and-eshaan-sriram-iyer/

Featured scientific publication:

Jessie Muir, Eshaan S. Iyer, Yiu-Chung Tse, Julian Sorensen, Serena Wu, Rand S. Eid, Vedrana Cvetkovska, Karen Wassef, Sarah Gostlin, Peter Vitaro, Nick J. Spencer & Rosemary C. Bagot Sex-biased neural encoding of threat discrimination in nucleus accumbens afferents drives suppression of reward behavior. Nature Neuroscience 27, 1966–1976 (2024). https://doi.org/10.1038/s41593-024-01748-7

https://doi.org/10.1038/s41593-024-01748-7

Brain Star Award Feature: Maira Belen Blasco, Douglas Research Institute, McGill University

Maira Belen Blasco

A reduction in the number of connexions between brain cells is seen in the early stages of psychosis and is associated with negative symptoms.

Schizophrenia is a complex psychiatric disorder typically emerging in adolescence or early adulthood. It is thought to occur because of alteration in the maturation or pruning of connexions between neurons called synapses. While this theory, called the synaptic theory is supported by genetic, stem cell and studies of brain of deceased patients, direct evidence to support this theory in living patients was doubtful. Maira Belen Blasco, working in the laboratory of Dr. Romina Mizrahi at the Douglas Research Centre, McGill University, investigated whether difference in the density of synapses could be seen in first-episode psychosis (FEP) and in clinical high risk (CHR) patients using positron emission tomography (PET). They found that synaptic density was reduced during the early stages of psychosis and its risk states and associated with negative symptoms.

Read the full story here: https://can-acn.org/brain-star-award-winner-maira-belen-blasco/

Featured scientific articleMaira Belen Blasco

Blasco MB, Nisha Aji K, Ramos-Jiménez C, Leppert IR, Tardif CL, Cohen J,  Pablo M Rusjan , Romina Mizrahi. Synaptic Density in Early Stages of Psychosis and Clinical High Risk. JAMA Psychiatry. 2024 Nov 13; Published online: https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2825648

https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2825648

Brain Star Award winner feature: Diego B. Piza, Western University

Diego B. Piza

Better understanding the role of vision in the brain’s representation of space by studying freely moving primates

The hippocampus is a structure of the mammalian brain that has been implicated in spatial memory and navigation. Its role has been primarily studied in nocturnal mammals, such as rats, that lack many adaptations for daylight vision. Here, Diego B. Piza, working in the laboratory of Julio Martinez-Trujillo at Western University, demonstrates that during 3D navigation, the common marmoset, a New World primate adapted to daylight, uses different exploration–navigation strategies compared to rats. He further shows that maps of space in the marmoset brain depend on vision-related cues and object relationships used as landmarks for navigation. It is likely that similar encoding mechanisms exist in other diurnal mammals, including humans.

To explore their environment, marmosets predominantly use rapid head-gaze shifts for visual exploration while remaining stationary. During active movement, marmosets stabilize their head, in contrast to rats, who use low-speed head movements to scan the environment as they locomote. This work suggests that spatial memory in primates may rely on anchoring sequences of views to specific places, providing a unique mechanism for encoding spatial experiences.

This publication represents a major technical and conceptual achievement in neuroscience.

Read the full story: https://can-acn.org/brain-star-award-winner-diego-b-piza/

Article citation

Piza, D.B., Corrigan, B.W., Gulli, R.A., Do Carmo, S., Cuello, A.C., Muller, L., Martinez-Trujillo, J. Primacy of vision shapes behavioral strategies and neural substrates of spatial navigation in marmoset hippocampus. Nat Commun 15, 4053 (2024). https://doi.org/10.1038/s41467-024-48374-2

https://doi.org/10.1038/s41467-024-48374-2

Postdoctoral Position – Gut Microbiome-Brain Axis in Amyotrophic Lateral Sclerosis

The Nguyen and Sharkey Labs at the University of Calgary and Hotchkiss Brain Institute are seeking motivated applicants for a postdoctoral position studying the gut microbiome-brain axis in amyotrophic lateral sclerosis (ALS).  Projects will involve gut microbiota manipulation and in vivo multiphoton imaging of the brain using animal models of ALS. The desired candidate will have experience in animal-based neuroscience research, and ideally, in vivo microscopy (in vivo cranial window imaging in the project with be done in collaboration with Drs. Alex Lohman and Grant Gordon). The successful applicant will be expected to work as part of a team while managing their independent project(s). Dr. Nguyen’s research program investigates the pathogenic mechanisms underlying ALS. Dr. Sharkey ’s research program focuses on gut physiology, the enteric nervous system and gut-brain axis. This position is funded through a CIHR Project Grant and Brain Canada Operating grant. The successful applicant will be encouraged to apply for extramural fellowship funding opportunities.

Individuals interested in this opportunity should submit in pdf format of the following via email to Dr. Minh Dang Nguyen (mdnguyen@ucalgary.ca) and Dr. Keith Sharkey (ksharkey@ucalgary.ca).

Nguyen lab: www.cytoskeletonexus.com

Sharley lab: https://cumming.ucalgary.ca/labs/sharkey/research

  • Letter of interest
  • Curriculum vitae
  • Any relevant publications (3 maximum)
  • Names and contact information of three referees (who will only be contacted if a candidate is shortlisted)

The position is located in Calgary, Alberta. Applications will be accepted until a suitable candidate is identified.

The terms and conditions of employment are covered under the UCalgary and PDAC Collective Agreement. To find out more about postdoctoral scholar program at the University of Calgary visit our Postdocs website.  

About the University of Calgary

UCalgary is Canada’s entrepreneurial university, located in Canada’s most enterprising city. It is a top research university and one of the highest-ranked universities of its age. Founded in 1966, its 36,000 students experience an innovative learning environment, made rich by research, hands-on experiences and entrepreneurial thinking. It is Canada’s leader in the creation of start-upsStart something today at the University of Calgary. For more information, visit ucalgary.ca.

About Calgary, Alberta

Calgary is one of the world’s cleanest cities and has been named one of the world’s most livable cities for years. Calgary is a city of leaders – in business, community, philanthropy and volunteerism. Calgarians benefit from the strongest economy in the nation and enjoy more days of sunshine per year than any other major Canadian city. Calgary is less than an hour’s drive from the Rocky Mountains and boasts the most extensive urban pathway and bikeway network in North America.

The University of Calgary has launched an institution-wide Indigenous Strategy committing to creating a rich, vibrant, and culturally competent campus that welcomes and supports Indigenous Peoples, encourages Indigenous community partnerships, is inclusive of Indigenous perspectives in all that we do.

As an equitable and inclusive employer, the University of Calgary recognizes that a diverse staff/faculty benefits and enriches the work, learning and research experiences of the entire campus and greater community. We are committed to removing barriers that have been historically encountered by some people in our society. We strive to recruit individuals who will further enhance our diversity and will support their academic and professional success while they are here. In particular, we encourage members of the designated groups (women, Indigenous peoples, persons with disabilities, members of visible/racialized minorities, and diverse sexual orientation and gender identities) to apply. To ensure a fair and equitable assessment, we offer accommodation at any stage during the recruitment process to applicants with disabilities. Questions regarding [diversity] EDI at UCalgary can be sent to the Office of Equity, Diversity and Inclusion (equity@ucalgary.ca) and requests for accommodations can be sent to Human Resources (hrhire@ucalgary.ca).

Brain Star Award Feature: Andrew Mocle, University of Toronto

Andrew Mocle

Better understanding how ensembles of neurons are recruited in memory formation.

The hippocampus is a critical brain region for encoding and recall of episodic memories. The physical trace left in the brain by memory formation is called an ‘engram’, and the process by which new engrams are formed is still unclear. In this work, Andrew Mocle, working in the laboratory of Sheena Josselyn, used advanced imaging techniques to track neurons and their patterns of activity before, during, and after memory encoding. The resulting data prompted a new engram formation model, whereby small ensembles of neurons (instead of individual cells) are allocated to an engram depending on their average excitability at the time of learning. The demonstration that highly-excitable ensembles are preferentially allocated to encode newly learned information represents a major conceptual advance in the study of how memories are stored in the brain.

Read more: https://can-acn.org/brain-star-award-winner-andrew-mocle/

Featured scientific publication: Mocle, Andrew J., Adam I. Ramsaran, Alexander D. Jacob, Asim J. Rashid, Alessandro Luchetti, Lina M. Tran, Blake A. Richards, Paul W. Frankland, and Sheena A. Josselyn. “Excitability Mediates Allocation of Pre-Configured Ensembles to a Hippocampal Engram Supporting Contextual Conditioned Threat in Mice.” Neuron 112, no. 9 (May 1, 2024): 1487-1497.e6.

https://doi.org/10.1016/j.neuron.2024.02.007

Brain Star Award Feature: Niklas Brake, McGill University

Niklas Brake

Better understanding the non-rhythmic components of Electroencephalography (EEG) can lead to better interpretation of brain activity

Article citation

Brake, N., Duc, F., Rokos, A., Arseneau, F., Shahiri, S., Khadra, A., and Plourde, G. (2024) A neurophysiological basis for aperiodic EEG and the background spectral trend. Nature Communications 15(1514). https://www.nature.com/articles/s41467-024-45922-8

Electroencephalography (EEG) has been in use for almost a century to study brain activity, during which time its rhythmic oscillations in signal, seen as waves of activity, have shaped a unique lens through which many researchers view the nervous system. Recently, interest has shifted toward seemingly non-rhythmic (i.e., aperiodic) EEG signals, which have been linked to various neurological conditions and states of consciousness. However, these findings have been primarily descriptive, leaving interpretations of these aperiodic signals elusive.
In this study, Niklas Brake, in the research group of Professor Anmar Khadra at McGill University and collaborating with anesthesiologist Dr. Gilles Plourde at the Montreal Neurological Institute, used biophysical modeling to show that large aperiodic fluctuations in the brain’s electric field arise from cortical circuits synchronizing with aperiodic dynamics. These fluctuations, in turn, can significantly bias traditional EEG interpretations. Additionally, the model predicted that both periodic and aperiodic EEG signals are shaped by the molecular timescales of the brain’s inhibitory pathways. To test this, they collected EEG data from individuals undergoing general anesthesia with propofol, a drug that alters the molecules underlying neural inhibition. The observed signal changes matched their model predictions. Using insights from the modeling, they developed an analysis method for identifying and removing aperiodic EEG signals, both to extract aperiodic features and to improve brain rhythm characterization. Applying this method to EEG data revealed that loss of consciousness from propofol was uniquely associated with an increase in delta rhythms, an observation that had previously been masked by propofol’s molecular effects.
Overall, this study extends EEG theory beyond neural oscillations, illustrating how EEG signals are shaped by neural mechanisms other than brain rhythms and revealing how these signals can undermine traditional analysis methods.

Read more: https://can-acn.org/brain-star-award-winner-niklas-brake/

Remembering Leo P. Renaud

It is with great sadness that we learned of the passing of Dr. Leo P. Renaud (1941-2025), distinguished Canadian neuroscientist and Past President of the Canadian Association for Neuroscience on 6th July, 2025. Leo had an iconic status in the field of Neuroendocrinology and indeed Canadian Neuroscience that was founded on his outstanding scientific contributions first at McGill University and later at the University of Ottawa ( https://can-acn.org/leo-renaud-honorary-member/). He trained several generations of scientists and clinicians during his lifetime and was an exemplary teacher, supervisor, colleague, role model and friend. His warmth, disarming sense of humour, and humanism made everyone who came in contact with him feel at ease and special. His loss is profound, but his legacy as a scientist and a model of humanity endure. Leo is survived by his wife, Lillian, and two daughters (Francine and Barbara) and we extend our deepest sympathies to them. 

Charles Bourque & Jack Jhamandas